Factors affecting the stability of soil aggregates of plinthosols in the middle reaches of the Yangtze River.

• The parent material of the plinthosol was wind-formed deposits. • The parent material had an impact on the aggregate stability. • The aggregate stability was also affected by the initial soil moisture and OM. • The aggregate stability of the red matrix and white veins differ significantly. Soil aggregate stability is a key factor that affects soil erosion and ecological restoration. In this study, three typical plinthosol profiles in Wuhan (W), Yueyang (Y), and Jiujiang (J) were selected, and the mean weight diameter (MWD), geometric mean diameter (GMD), and fractal dimension were used as indicators of soil aggregate stability, as well as the erodibility factor (K value). Based on the end-member analysis, it appears that the plinthosols in the three profiles were wind-formed deposits, which greatly affected particle size and erodibility. There was a greater resistance to erosion among the plinthosols developed from finer grains than among those developed from coarse grains. The stability of aggregates in profiles W and Y decreased gradually with depth, while it varied little in profile J. The initial moisture content had a significant effect on the anti-erodibility of the plinthosols, and there were some differences between the profiles: in profile W, the anti-erodibility increased with the increase in initial moisture and reached its maximum value at the initial moisture content of 20%; in profiles Y and J, when the initial moisture content was 15%, the anti-erodibility was the highest. Reddish matrix had a higher anti-erodibility than white veins. Profile J had the largest stability gap between white veins and reddish matrix, followed by profile Y and W. These results provide a theoretical basis for the conservation of soil and water in the Yangtze River middle reaches by revealing the stability characteristics of plinthosols. [ABSTRACT FROM AUTHOR]